Looks like spat5.osc.route always return a list, even if it contains only 1 element.
In Max, some objects may complain about it :
for example, if you connect the output of spat5.osc.route to right inlet of a [*~], Max complains :
*~: inlet: list: wrong message or type
Here is a simple patch showing the issue.
using [printit] (from CNMAT package) I can see that the output of spat5.osc.route is always a list
printit: printit: received LIST with 1 argument(s):
----------begin_max5_patcher----------
701.3oc0XEsaaBCE8Y3q.YsmlxxvFLA1GvdduOUU4PcybGXhLltLU08sOiMn
z1PCdo1oKujHtX74dt2SN9RdHL.rtYGsED8knuGED7PXPfNTeffgqC.0jckU
jV8x.2V0v6pAKL2ZKQV9CFey0BZozrMIEEKiWDAyi6+Bq+DgVFGc0vyndbFu
hJ06GbevlN4XTzPzaaD0D89lMDgciNKZVe2mfn8YgfTSkTw0TNYcEseIwC2y
rqxeukZRO.XQDXMguADcU+JdLLr+iEVReN8WJrGAVR2oyNvG+ywpHnDcQHEo
qHIGuhflrh.mf+IfWiisrMbRkSY3VAiKYxi13wOklqNkFe7DzLEbBrXdYpIA
Wk5aUJ9cPkVSaaIanGzD+7FBiG8A370EXbtMcQ6EqYupX0oxTgZ6oQZdZAIS
yMbM9TXIZBVtBbrF5owzYkxYvryii6pKDCWbZrOLbK9+xuMCh7heKzK9sXiS
q28aStrraGJKt1t8L411rzN+1QVZoeKzZ+1iZ290tppuQJ+IU5IiWXBzX7h8
8PDwuCp54oetQtFW3Y5megbtSZgON1A6kicls6lqy+rbO2aSur7qMUEXLxo1
0nyic87yT.Qo9XlBDF3NVzpxa7xl1RKO7YnkMb1CpvQm8fP+Cy5qwBTw3u7O
aQmu8wedcnsoSTNtciuYQz9T9FZqjwIRVC+oKB8rE0HtgJzcjIK9tE5zogFd
FfVMxWD7PnQuMnyrA5g76sgD1FjxbARV.zJuHgrggPunfr.4BenerR93fdZh
E33BsStE3fvN.nTa.xA3fPV.D1GRCqPFg8wOGrB5921v8d.VQ5CarlSNIa2d
OUzNrZMFpYEtqQmWEKzWx3lK0ye.Dz6YiqGqiPDpICjpwB5D57BrKyL7IntQ
wPdGan9pXmBR8bHb0Hop4MLDQOtR3ig+E7Gy.aB
-----------end_max5_patcher-----------
Of course there are workarounds : inserting a [float] or [number] converts the list back to float… but this extra step shouldn’t be necessary :-s